.jump{
    background-color: black;
    padding: 50px 0;
}
.jump span{
    position: relative;
    font: normal 500 2rem 'Varela Round', sans-serif;
    color: white;
    animation: bounce 1s cubic-bezier(0.05, 0, 0.2, 1) infinite alternate;
    top: 0px;
}
span:nth-child(1) {
  animation-delay: 0s;
}
span:nth-child(2) {
  animation-delay: 0.5s;
}
@keyframes bounce {
  0% {
    top: 0;
    text-shadow: rgba(255, 255, 255, 0.4) 0 0 0.05em;
  }
  100% {
    top: -1em;
    text-shadow: rgba(255, 255, 255, 0.9) 0 1em 0.35em;
  }
}